Four years ago, industry designed a new extension cord to keep children from being burned when they put cord receptacles in their mouths. It asked a new federal safety agency for help in imposing the design on every extension cord sold in America.

It is still waiting for that help, and cords still burn children.

The agency is the Consumer Product Safety Commission. Created with a sense of urgency and high hopes, it has responded with prolonged delays and small accomplishments.

Largely because of internal chaos, the agency has for the most part failed to perform the mission entrusted to it by Congress - to use strong new laws to better protect buyers from the unneccessary hazards of consumer goods.

It was created in 1972 on the recommendation and findings of the National Commission on Product Safety. Those findings: 20 million Americans are injured each year in incidents involving consumer products. Of the victims, 30,000 are killed, 110,000 permanently disabled.

Given broad new powers to reduce that toll, the Consumer Product Safety Commission has used that authority to write mandatory safety standards for only three products, and that took years.

Three years for safety standards for glass used in doors, windows and walls.

Two and one half years for matchbook covers.

And two years for its sadly laughable action on swimming pool slides. It was the first mandatory safety standard the agency wrote under its 1972 charter, was designed to end accidents resulting in paralysis and occupied 15 pages in the Federal Register.

The heart of the regulations was a series of warning plaques at mandatory levels on slide steps, including one describing a federally approved-as-safe belly slide: "Head Up - Arms Straight Ahead - Fingers Pointing Up."

Yet at the same time, far more common safety and far more pervasive health hazards have been - and still are - unaddressed.

For example, the study commission on product safety found that the real hazard with swimming pools was child drowning for lack of suitable fencing. Moreover, the product safety commission still has no policy on what to do about chronic hazards, like ingredients that can cause cancer.

Now the commission is under increasing outside pressure to perform, to end the bureaucratic delays that have kept it groping for two years to write safety standards for public playground equipment, two years for aluminum wiring, more than two years for color television sets, almost three years for power rotary lawn mowers.

Even its recent ban on children's sleepwear containing Tris, a cancer-linked chemical fire retardant, took almost 13 months after the Environmental Defense Fund asked for a ban.

"This month marks the fourth anniversary of te Consumer Product Safety Commission," notes Sen. Wendell H. Ford (D-Ky.), chairman of the Consumer Subcommittee, "although its accomplishments barely rival those of an agency one-tenth its age."

"It's an agency with abundant powers that has managed to tie itself in knots," says a congressional staff member who follows the commission.

A Civil Service survey last November found that only 43 per cent of the agency's employees thought it was doing a good job.

Delays are not the only lightning rod for assaults on the agency. Among other problems:

It frequently acts only when presented with hazards by outside pressure groups, such as the Environmental Defense FUnd.

It has reduced efforts to enforce several other laws it administers, despite sampling programs that have found widespread noncompliance by industry, including a 50 per cent compliance rate for electric toys.

It has failed to develop procedures to assure that more consumer products recalled for safety defects are returned and repaired. In one period, only 12 per cent of 6 million recalled items were fixed.

It has spun its wheels over administrative matters and minor safety issues at the expense of a vigorous attack on unreasonable hazards in consumer goods. "It's been dealing with a lot of trivia rather than hitting the gut issues," says another congressional staffer.

To be sure, the commission probably could never have lived up to the high sea of hopes on which it was launched.

Congress had been approaching safety on a piecemeal basis; the full legislative machinery had earlier been brought to bear, for example, on a two-page law barring the sale opened from the inside.

So Congress created a commission with broad authority to regulate the safety of consumer products. In part, the agency's failure stems from its small size and the nature and vastness of that task - the job of injecting governmental will into the greatest intimacies of manufacturing, the shape and content of a product. There are 890 employees in the $40 million-a-year Consumer Product Safety Commission. There are 10,000 categories of consumer products. There are 2.5 million manufacturers.

Too, the agency operates under the constraints of the various laws it enforces and the virtual certainty of court challenges because of the financial impact of its actions. Commissioners have lamented in public and in private their need for an airtight case against a product if they are to, say, banish it from the market. But injury data may be lacking and scientific findings questioned.

At a hearing on cancer-causing asbestos in some products last month, Commissioner Barbara Franklin moaned: "There is a hazard, and I think we need to do something now. But it is not clear to me we have the right kind of or enough information" for an across-the-board ban on asbestos. So she and a commission majority voted not for a ban on asbestos goods but for a major study of them.

Despite these obstacles, it is almost universally agreed that the commission still has not done nearly what it could and should do.

And overwhelmingly the critics - in Congress, within the commission and among those who deal with it - attribute the agency's failures to the two men who have served as chairman of the five-member body:

Richard O. Simpson, the first chairman from May, 1973, to June, 1976. Simpson is described as a capable engineer but inept administrator who allowed project upon project to pile up - 180 of them - on a small staff that was given no sense of which to do first. A fellow commissioner facetiously said Simpson has "not gotten full credit for the damage he's done."

Simpson describes his three years as a "shakedown cruise" for a new agency and disputes statements that he left a managerial mess. Under him, Simpson said, the commission was making measurable progress toward a safer marketplace.

S. John Byington, chairman since June 2, 1976, and controversial from the time President Ford nominated him. The Senate refused to give him a seven-year term, gave him a 2 1/2 years instead; both terms were opposed by consumer groups. In his first 11 months in office he has been on travel status for 54 work days to such spots as St. Thomas, Tokyo, Bonn, Geneva, Hong Kong and statewide field offices.

He has packed his office with eight high-level staffers, compared with Simpson's one. Sen. Ford calls that part of the agency's problem; Byington calls it part of the solution.

Like a dervish, Byington has whirled through the Commission with a controversial series of reorganizationns and administrative moves designed to bring order to the agency.

"The problem is, we have had two not-good chairmen," one commissioner laments privately. "One couldn't manage and one overmanages."

In a memo to Byington last month, Commissioner Franklin echoed the sentiment: "Whether or not the reorganization will best serve product safety and personnel productivity and morale is, unfortunately, an open question to me.My chief impression . . . is that the net effect of the reorganization may be an overbundance of planners and managers. Strange as it may sound in view of the dearth of this kind of leadership in the past, I fear the agency now may be careening too far in the other direction."

The Civil Service survey also found that only 40 per cent of the agency's employees felt their work was planned and 42 per cent felt they received conflicting assignments. Because the law gives administrative and budgetary control of the agency to the commission chairman, some commissioners say that agency failures are primarily the chairman's. They maintain that once a matter is brought to the full commission, the five act without undue delay.

Byington claims that his management changes are beginning to bring results; the commission has recently taken major steps toward safer power mowers and safer matchbooks and has levied thousands of dollats in civil penalties on two firms that, the commission said, failed to report safety defects timely.

Others say, however, that the activity is the product of congressional prodding or that most of it would have happened anyway. Thay say the reality of performance has yet to match Byington's rhetoric of promise.

"I see a flurry of activity but little progress," Sen. Ford wrote Byington after three days of oversight hearings. "There has been an overemphasis on globe-trotting and speeching to inform the world of the commission's existence and an underemphasis on meaningful safety initiatives . . . "

Ford gave Byington 100 days to produce decisive action on 12 matters - including extension cords.

The dearline is designed to end the chronic relays that have thwarted the agency from making significant progress toward reducing the most common consumer hazards, as identified in the two-year federal study that gave rise to the commission.

For example: the commission published a notice on May 28, 1974, that it would establish mandatory safety standards for glass used in doors, windows and walls, those standards will take effect July 6.

There are about 150,000 victims each year of accidents involving broken windows, glass doors and walls, and many need not be seriously injured if glass were safety-glazed, according to the National Commission on Product Safety.

Thus, about 450,000 people have been injured in architectural glazing accidents since the safety commission declared its intention to make building glass safer And an unknown number buildings have been constructed with ordinary glass that will remain a potential killer and maimer.

Some commissioners say the adoption of such mandatory safety standards is slowed by Congress' requirement that the standards be writtedn by outside groups under contract to the commission. What has happend, says Commissioner David Pittle is that much of the work has to be re-done, in some cases to provide a defense against any court challenges.

The commission's small staff then must interrupt other work, delaying it. Or such things as product recalls may delay the safety standards. Byington says he has instituted new procedures designed to avoid duplication of work by closer supreviscy on chronic hazards - elements that may cause cancer orcy on chronic hazards - elements that may cause cnacer or other health problems years after exposure to them. Last week it joined with other agencies responsible for a safer marketplace - the Food and Drug Administration and the Environmental Protection Agency - to phase out aerosol fluorocarbons.

Also responsible for four other consumer laws, the commission has under consideration standards for flameproof upholstery under the Flammable Fabrics Act; unsteady refuse bins under the Hazardous Substances Act; childproof caps on pills containing high levels of iron under the Poison Prevention Packaging Act. And it also enforces that Befrigerator Safety Act.

Under these laws, it also has set safety standerds for bicycles and some children's toys, banned fireworks and vinyl chloride sprays and unsafe cribs. It has overseen the recall of some 25 million items.

But the sentiment is that not enough has been done. Says Rep. John E. Moss (D-Calif.), principal House author of the legislation that created the commission: "What we are faced with is timidness on part of the commission. If it dose not improve this performance, it might as well be eliminated and its duties given back to those who handled them so inexpertly before."

That would be a tragedy to Moss and others, for whom the commission should be a check on the technology, the chemistry and the business practices that make the marketplace needlessly unsafe.